Short message service support over a packet-switched telephony network

Abstract

According to an embodiment of the present invention, a system is provided that includes a cellular network, a Public Switched Telephone Network (PSTN) and a mobile IP-telephony network (MIPTN). Both the cellular network and the MIPTN include a Home Function and one or more visited Functions. MIPTN subscribers can roam within the MIPTN. Also, a Gateway Function interfaces the PSTN and the MIPTN to allow roaming between the cellular network and the MIPTN. The Gateway Function performs a dynamic mapping function between PSTN/cellular addresses (e.g., in E.16440 format) and MIPTN addresses (e.g., IP addresses) to allow registration and call delivery for subscribers roaming between the cellular network and the MIPTN. A similar type of Gateway Function also allows Short Message Service (SMS) messages to be delivered over the MIPTN as well.

What is claimed is:  
     
       1. A method of delivering a short message over a packet-switched telephony network comprising: 
       receiving a short message, including a subscriber identification which identifies a cellular subscriber to receive the short message;  
       forwarding the short message and subscriber identification to a first gateway function;  
       the first gateway function obtaining subscriber location information from the subscriber's cellular home function, the location information including a cellular network address of a second gateway function through which the subscriber can be reached;  
       forwarding the short message and the subscriber identification to the second gateway function;  
       the second gateway function using a dynamic mapping obtained during registration to identify a packet-switched telephony network address of a packet-switched telephony visited function where the subscriber is located; and  
       the second gateway forwarding the short message to the packet-switched telephony visited function where the subscriber is located.  
     
     
       2. The method of  claim 1  and further comprising forwarding the short message from the packet-switched telephony visited function where the subscriber is located to the subscriber terminal. 
     
     
       3. A method of delivering a short message over a packet-switched telephony network comprising: 
       receiving a short message, including a subscriber identification which identifies a packet-switched telephony subscriber to receive the short message;  
       forwarding the short message and subscriber identification to a first gateway function;  
       the first gateway function obtaining subscriber location information from the subscriber's packet-switched telephony home function, the location information including a packet-switched telephony network address of a second gateway function through which the subscriber can be reached;  
       forwarding the short message and the subscriber identification to the second gateway function;  
       the second gateway function identifying a cellular network address of a cellular visited function where the subscriber is located; and  
       the second gateway forwarding the short message to the cellular visited function where the subscriber is located.  
     
     
       4. The method of  claim 3  and further comprising forwarding the short message from the cellular visited function where the subscriber is located to the subscriber terminal. 
     
     
       5. A method of delivering a short message over a packet-switched telephony network comprising: 
       receiving a short message, including a subscriber identification which identifies a cellular subscriber to receive the short message;  
       forwarding the short message and subscriber identification to a first gateway function;  
       the first gateway function obtaining subscriber location information from the subscriber's packet-switched telephony home function, the location information including a packet-switched telephony address of a second gateway function through which the subscriber can be reached;  
       forwarding the short message and the subscriber identification to the second gateway function;  
       the second gateway function using a dynamic mapping obtained during registration to identify a cellular address of a cellular visited function where the subscriber is located; and  
       the second gateway forwarding the short message to the cellular visited function where the subscriber is located.  
     
     
       6. A method of delivering a short message over a packet-switched telephony network comprising: 
       receiving a short message at a cellular network short message service center, including a subscriber identification which identifies a cellular subscriber to receive the short message;  
       forwarding the short message from the message service center to a gateway function including the subscriber identification;  
       obtaining from the subscriber's cellular home function a cellular address of a gateway function where the subscriber can be reached;  
       forwarding the short message and the subscriber identification to the gateway function;  
       the gateway function using a dynamic mapping obtained during registration to identify a packet-switched telephony address of a packet-switched telephony visited function where the subscriber is located based on the subscriber identification;  
       the gateway function sending the short message to the packet-switched telephony visited function where the subscriber is located.  
     
     
       7. A method of delivering a short message over a packet-switched telephony network comprising: 
       receiving a short message at a packet-switched telephony short message service center, including a subscriber identification which identifies a packet-switched telephony subscriber to receive the short message;  
       forwarding the short message from the message service center to a gateway function including the subscriber identification;  
       obtaining from the subscriber's packet-switched telephony home function a packet-switched telephony address of a gateway function where the subscriber can be reached;  
       forwarding the short message and the subscriber identification to the gateway function;  
       the gateway function using a dynamic mapping obtained during registration to identify a cellular address of a cellular visited function where the subscriber is located based on the subscriber identification;  
       the gateway function sending the short message to the cellular visited function where the subscriber is located.